Flow cytometric (FCM) analysis was used
to assess the potential impact of chronic radionuclide exposure in fish
populations inhabiting contaminated sites in the vicinity of the Chernobyl
nuclear accident. Four species of fish, channel catfish (Ictalurus punctatus),
crucian carp (Carassims carassius), carp (Cyprinus carpio) and
tench (Tinca tinca), were collected within a lokm radius of the Chernobyl
Nuclear Power Plant and compared with 'control' populations from two
uncontaminated locations far removed front the plant. Assays of whole blood, as
well as separate erythrocyte and leukocyte components, revealed aneuploid-like
patterns in the DNA histograms of some fish, as well as widened G0/G1
peaks. None of the fish collected from the uncontaminated sites demonstrated
these kinds of changes in their DNA histograms. Increases in the coefficient of
variation (CV) of the G0/G1 peak, indicating abnormal DNA
distributions, were observed in- several of the fish from Chernobyl relative to
the control populations. Cell cycle perturbation in fish from the contaminated
sites was also detected, with a higher percentage of cells in G2/M
phase relative to the controls. Leukocytes proved more sensitive than
erythrocytes, as they displayed a larger number of abnormal DNA histograms.
Variations in the cellular DNA content similar to those reported here have been
shown for other vertebrate species exposed to radiation and other genotoxic
agents in laboratory and field settings.